Biotic Stress/Applied Plant Bio
CS-3-5 - A Histone Deacetylase Regulates Cytokinin-Induced Priming
Sunday, July 15
2:23 PM - 2:43 PM
Priming is the indirect enhancement of the immune response of plants to pathogens. Compared to unprimed plants, the immune response from primed plants, upon pathogen attack, is much stronger. Recent research in Arabidopsis thaliana has shown that the plant hormone cytokinin has a priming effect against biotrophic pathogens, a phenomenon we call cytokinin-induced priming. The molecular mechanisms behind priming remains largely unknown, although recent studies have indicated that chromatin modifications, such as acetylation/de-acetylation, may play a role. Here, we show that cytokinin perception is necessary for the action of other chemicals that have known priming activity. Further, using a gene expression meta-analysis, we identify a histone deacetylase (HDAC) whose expression is regulated by cytokinin. We show through genetic analyses that this HDAC functions as a negative regulator of cytokinin-induced priming. Chromatin mapping using Assay for Transposase-Accessible Chromatin using sequencing (ATAC-Seq) indicates that priming by cytokinin involves differential regulation of genes involved in nitrogen assimilation, metabolism, and amino acid transport which alters the susceptibility of the plant to pathogens. We propose a model in which cytokinin-induced chromatin regulation of overall nitrogen status in plants functions as a new and general mechanisms of defense priming against biotic stress.
Dawn Hajdu – Colorado State University ; Daniel Bush – Colorado State University; Cristiana Argueso – Colorado State University